# Relationship history for MSHA mine 2401503

Current hierarchy: **Hilde David W → Hilde Construction Company Inc → Hilde Wash Plant**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Hilde David W → Hilde Wash Plant; 1978-03-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hilde Construction Company Inc → Hilde Wash Plant; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hilde David W → Hilde Construction Company Inc; 1979-01-01 to current/open; source msha-controller-operator-history